High-barrier packaging materials find particular application in the food industry, including for example, bags, pouches and cups for storing food products for human or animal consumption. A high-barrier packaging material is defined as providing very low transmission rates for water vapor and oxygen gas at both standard and tropical conditions. Packages having low water vapor and oxygen transmission rates are linked to extended life of food stored therein. Water vapor and oxygen transmission are accelerated at higher temperature and humidity (tropical conditions). They act as the main culprits in degradation of food stored in packages.
High-barrier packaging materials in use today include a combination of plastic polymer films and metal foils, manufactured by lamination and extrusion technologies. These types of plastic and foil based high-barrier packaging materials have high material costs, as compared to lower cost materials such a paper and paperboard. Further, these conventional high-barrier materials are not biodegradable or recyclable. Paper based packaging materials are desirable because they have comparatively low material costs, and are recyclable and biodegradable. However, paper and paperboard, being hygroscopic and porous are considered unsuitable for high-barrier applications.
There is a need for a high-barrier packaging material that has low transmission rates for water vapor and oxygen gas at both standard and tropical conditions and which is recyclable, substantially biodegradable and/or compostable.